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. 1979 Oct;76(10):4842–4846. doi: 10.1073/pnas.76.10.4842

Origin of observed changes in 14N hyperfine interaction accompanying R → T transition in nitrosylhemoglobin

S K Mun 1,2, Jane C Chang 1,2,*, T P Das 1,2
PMCID: PMC413033  PMID: 228268

Abstract

Theoretical investigations of electronic distributions in eight different structural forms of nitrosylhemoglobin were carried out to study the changes in 14N hyperfine interaction observed with the transition from R to T structures under the influence of inositol hexaphosphate or changing pH. Four of the eight forms studied consisted of protonated and deprotonated Npros in the proximal imidazole ligand with linear and bent Fe—N—O structures. Two other forms had a straight Fe—N—O structure and Fe—Im bond stretched by 0.5 and 1.0 Å. The other two systems we have studied are five-liganded NO-heme with bent and straight Fe—N—O structures. Our investigations show that arrangements of energy levels did not differ significantly among all the structures, the unpaired electron always occupying an antibonding orbital with dz2 symmetry. The protonated and deprotonated systems with either linear or bent Fe—N—O structure showed substantial hyperfine interaction of the 14N nuclei of the NO group and the Nε atom of the proximal imidazole, indicating that a 9-line electron spin resonance hyperfine pattern (R structure) would be expected in all four cases. On the other hand, the extensions of the Fe—Im bond produce a sizeable decrease in the 14Nε hyperfine interaction, indicating that an extension beyond 1.0 Å would provide a 3-line hyperfine pattern close to that found for the five-liganded NO-heme system. Our results thus provide quantitative support for the model of severe extension or cleavage of the Fe—Nε bond proposed in the literature for explaining the R-to-T transition of the α-chain of nitrosylhemoglobin.

Keywords: proximal imidazole, severe extension, cleavage

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Chevion M., Stern A., Peisach J., Blumberg W. E., Simon S. Analogous effect of protons and inositol hexaphosphate on the alteration of structure of nitrosyl fetal human hemoglobin. Biochemistry. 1978 May 2;17(9):1745–1750. doi: 10.1021/bi00602a025. [DOI] [PubMed] [Google Scholar]
  2. Chien J. C., Dickinson L. C. Nonequivalence of subunits in [15N]nitrosylhemoglobin Kansas. A single crystal electron paramagnetic resonance investigation. J Biol Chem. 1977 Feb 25;252(4):1331–1335. [PubMed] [Google Scholar]
  3. Dickinson L. C., Chien J. C. An electron paramagnetic resonance study of nitrosylmyoglobin. J Am Chem Soc. 1971 Oct 6;93(20):5036–5040. doi: 10.1021/ja00749a011. [DOI] [PubMed] [Google Scholar]
  4. Henry Y., Banerjee R. Electron paramagnetic studies of nitric oxide haemoglobin derivatives: isolated subunits and nitric oxide hybrids. J Mol Biol. 1973 Feb 5;73(4):469–482. doi: 10.1016/0022-2836(73)90094-6. [DOI] [PubMed] [Google Scholar]
  5. Kon H., Kataoka N. Electron paramagnetic resonance of nitric oxide--protoheme complexes with some nitrogenous base. Model systems of nitric oxide hemoproteins. Biochemistry. 1969 Dec;8(12):4757–4762. doi: 10.1021/bi00840a016. [DOI] [PubMed] [Google Scholar]
  6. Kon H. Paramagnetic resonance study of Nitric Oxide hemoglobin. J Biol Chem. 1968 Aug 25;243(16):4350–4357. [PubMed] [Google Scholar]
  7. Maxwell J. C., Caughey W. S. An infrared study of NO bonding to heme B and hemoglobin A. Evidence for inositol hexaphosphate induced cleavage of proximal histidine to iron bonds. Biochemistry. 1976 Jan 27;15(2):388–396. doi: 10.1021/bi00647a023. [DOI] [PubMed] [Google Scholar]
  8. Mun S. K., Chang J. C., Das T. P. Critical appraisal of electronic structure of metmyoglobin. 14N and 57Fe hyperfine interactions. Biochim Biophys Acta. 1977 Jan 25;490(1):249–253. doi: 10.1016/0005-2795(77)90126-x. [DOI] [PubMed] [Google Scholar]
  9. Nagai K., Hori H., Yoshida S., Sakamoto H., Morimoto H. The effect of quaternary structure on the state of the alpha and beta subunits within nitrosyl haemoglobin. Low temperature photodissociation and the ESR spectra. Biochim Biophys Acta. 1978 Jan 25;532(1):17–28. doi: 10.1016/0005-2795(78)90443-9. [DOI] [PubMed] [Google Scholar]
  10. Peisach J. An interim report on electronic control of oxygenation of heme proteins. Ann N Y Acad Sci. 1975 Apr 15;244:187–203. doi: 10.1111/j.1749-6632.1975.tb41531.x. [DOI] [PubMed] [Google Scholar]
  11. Perutz M. F., Kilmartin J. V., Nagai K., Szabo A., Simon S. R. Influence of globin structures on the state of the heme. Ferrous low spin derivatives. Biochemistry. 1976 Jan 27;15(2):378–387. doi: 10.1021/bi00647a022. [DOI] [PubMed] [Google Scholar]
  12. Rein H., Ristau O., Scheler W. On the influence of allosteric effectors on the electron paramagnetic spectrum of nitric oxide hemoglobin. FEBS Lett. 1972 Jul 15;24(1):24–26. doi: 10.1016/0014-5793(72)80817-2. [DOI] [PubMed] [Google Scholar]
  13. Salhany J. M., Ogawa S., Shulman R. G. Correlation between quaternary structure and ligand dissociation kinetics for fully liganded hemoglobin. Biochemistry. 1975 May 20;14(10):2180–2190. doi: 10.1021/bi00681a022. [DOI] [PubMed] [Google Scholar]
  14. Salhany J. M., Ogawa S., Shulman R. G. Spectral-kinetic heterogeneity in reactions of nitrosyl hemoglobin. Proc Natl Acad Sci U S A. 1974 Sep;71(9):3359–3362. doi: 10.1073/pnas.71.9.3359. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Scheidt W. R., Frisse M. E. Nitrosylmetalloporphyrins. II. Synthesis and molecular stereochemistry of mitrosyl-alpha, beta, gamma, delta,-tetraphenylporphinatoiron (ii) J Am Chem Soc. 1975 Jan 8;97(1):17–21. doi: 10.1021/ja00834a005. [DOI] [PubMed] [Google Scholar]
  16. Scholler D. M., Wang M. Y., Hoffman B. M. Resonance Raman and EPR of nitrosyl human hemoglobin and chains, carp hemoglobin, and model compounds. Implications for the nitrosyl heme coordination state. J Biol Chem. 1979 May 25;254(10):4072–4078. [PubMed] [Google Scholar]
  17. Sharma V. S., Ranney H. M. The dissociation of NO from nitrosylhemoglobin. J Biol Chem. 1978 Sep 25;253(18):6467–6472. [PubMed] [Google Scholar]
  18. Szabo A., Perutz M. F. Equilibrium between six- and five-coordinated hemes in nitrosylhemoglobin: interpretation of electron spin resonance spectra. Biochemistry. 1976 Oct 5;15(20):4427–4428. doi: 10.1021/bi00665a013. [DOI] [PubMed] [Google Scholar]
  19. Takano T. Structure of myoglobin refined at 2-0 A resolution. I. Crystallographic refinement of metmyoglobin from sperm whale. J Mol Biol. 1977 Mar 5;110(3):537–568. doi: 10.1016/s0022-2836(77)80111-3. [DOI] [PubMed] [Google Scholar]
  20. Wayland B. B., Olson L. W. Spectroscopic studies and bonding model for nitric oxide complexes of iron porphyrins. J Am Chem Soc. 1974 Sep 18;96(19):6037–6041. doi: 10.1021/ja00826a013. [DOI] [PubMed] [Google Scholar]

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